Numerical simulation of properties of a LPG flame with high-temperature air

This work is connected with properties of a flame obtained by combustion of liquified propane gas (LPG) with highly preheated air using a regenerative burner. The attention is focused on both the size and shape of the flame and the results were obtained in a semi-industrial furnace equipped with a regenerative burner system. Results of the CFD-based mathematical modeling have been compared with measurements of a number of parameters including the furnace-wall temperature and the concentrations of gaseous species in the furnace. The results indicate that the flame spread can be well predicted using the numerical model. A flame entrainment ratio has been proposed here for describing and classifying the physical changes of the flame shape. This ratio can be used to optimize the diameter and length of a combustion chamber for specific applications. It is also found that equipping a furnace with a regenerative burner can provide a high saving energy, a larger flame volume and a lower emission of NO. It has been obtained that a lower excess air ratio leads to a low peak temperature and a larger flame volume, thus a lower NO emission.